Critical Mass
by trufflemores
Summary: On permanent hiatus.
1. Prologue

**Author's Notes: Prologue is E2 Barry POV. Enjoy!**

 _Earth Two. Tuesday evening, 6:01 PM._

"It has been eight months since The Flash was last seen.

"Rumors of his death remain unconfirmed, but no one has been able to verify his whereabouts. We will continue to search until we find definitive evidence either way, or until such a time that it becomes irrelevant."

The TV is white noise to Barry as he sifts through his computer files, looking for – something. Anything. It's been a long day, but it's been a longer eight months. Shifting moods won't stop him from pursuing what he needs to in order to bring justice to the city. They deserve to know what happened to their hero. Besides, The Flash is the _only_ person who has ever attempted to fight Zoom. His death would be disheartening beyond belief, and it's an ache in Barry's chest he can scarcely bear, but the truth is too important to exclude the possibility.

Barry has to know. He has to know happened to The Flash.

Then, maybe, he brace himself for the fact that there will not be a war.

There will be only _Zoom_.

His hands are shaking slightly and he's got a pounding headache behind his eyes, but with catastrophe looming, he can't afford the luxury of sleep. They only have one hope. _Find The Flash_.

Clicking away at his keyboard, searching for _something_ , he's only half-listening to the anchorwoman as she continues.

"Sightings of The Flash have been fleeting over the past three years, but recently The Flash made one of his first truly public debuts at S.T.A.R. Labs. Despite our sincerest attempts to recognize the man underneath the helmet, no one was able to identify the speedster by film. A technical malfunction ensued after a power surge, and eyewitnesses were not able to confirm the identify the speedster.

"Shortly after this visit, S.T.A.R. Labs ceased all activities, following the sudden disappearance of its CEO, Dr. Harrison Wells. It has not been operational since.

"Dr. Wells has been missing for almost six months. While speculation continues to engage the Internet, no one has been able to positively identify the cause of his disappearance or locate his current whereabouts. At this time it is unknown what condition he is in.

"Dr. Wells' daughter, Jesse, has also not been seen since her abduction from Central City College six months ago. We cannot confirm her location or condition at this time, but strong evidence correlates with the theory that she was taken by Zoom."

"CCPD Captain Joe West is here with us to offer his take on the situation. Captain West, thank you for joining me here today."

"My pleasure."

Barry looks up at the screen, his fingers stilling on the keyboard. Seeing Joe on TV is reassuring: he always exudes a certain sense of unflappability and he's level-headed, honest without being brutal. Central City has relied on him dozens of times to confirm that despite the surge in meta-human activity, The Flash has been equally busy and drastically reduced casualties. Central City Police Department has been taking care of the rest.

Once, Barry might have smiled to see him on TV, talking about The Flash.

It's been hard to smile lately.

He never got close enough to The Flash to actually know him, but The Flash is Central City's and it feels quieter without him.

And more dangerous.

The anchorwoman holds a microphone to Joe's face and asks, "Captain West, what can you say about rumors that Zoom killed The Flash?"

Joe looks tired, but he keeps his voice steady as he responds. "I highly doubt it. If he had, we would know. Zoom would never take the city without taking The Flash, too."

"Is it possible that The Flash is being held hostage by Zoom?"

"Anything is possible," Joe replies. An echo of a smile crosses Barry's face. There was a time when Joe would have told him that only probable things were possible without understanding the difference, but the truth is far more extraordinary: _anything_ is possible. The Flash is living proof of that. As is Zoom. "However, I think it's unlikely," Joe adds calmly. "There's no point in holding The Flash alive."

"Care to elaborate?"

"Sure." Joe has the perfect voice for TV: calm, clear, and offering the right amount of emotional emphasis on every line. "Zoom is too dangerous at this time for the CCPD to confront. We've worked hard to minimize the damage he causes and reduce the number of fatalities, but we don't have a way to contain him. The Flash appears to be one of the few people who _can_. Once The Flash is out of the equation, Zoom can do what he wants until CCPD finds a way to stop him. Keeping The Flash alive and captive only presents the risk that The Flash could kill him from the inside. No." A head shake, almost rueful, because uncertainty is so rampant it's exhausting. "Zoom doesn't have The Flash."

"You say that CCPD has no way to stop Zoom," the anchor reiterates. "If Zoom is unstoppable, what does that mean for the city?"

Joe's lips twitch in an enigmatic smile. It isn't happy. "It means we're in a hell of a lot of trouble."

The anchor seems to sense that she won't get any more definitive answers and switches to a new topic. "The CCPD has released documents showing that crime rates have remained unusually low throughout the city. Why?"

"People commit crimes because they know there is a risk of getting caught, but the odds are still good enough that they take that chance anyway," Joe explains, straightening his shoulders like he's speaking to a fellow officer instead of a silver screen. "Being caught is bad, but that's only if you're caught. Enter Zoom: suddenly being caught doesn't mean a lengthy court procession followed by a sentence, it's flashing a light in the darkness to say 'Here I am. This is what I am capable of.' We've seen from other organized crime that either recruitment or extermination follow. Under those circumstances, even regulars like the Weather Wizards are lying low."

"Do you believe Zoom is operating alone at this time?" the anchor asks. There's a rumble of thunder in the distance, catching Barry's attention briefly as he looks outside the window, a vast swath of gray creeping over the city. Thundersnow.

"Yes," Joe says simply. "Zoom doesn't need–"

Barry doesn't catch the rest of what Joe says as the power goes out, plunging him into quasi-darkness.

His heart is racing as he reaches for his phone and stands, using the flashlight feature to illuminate the room.

Like something from a nightmare, Zoom is standing right in front of the door.

"How nice," he says in a voice that rumbles like an alligator's as Barry retreats, frozen step by frozen step, towards the back door. "You think you can know me."

Then Zoom's hand comes around his throat and Barry is gasping, the world tilting dangerously as he's held almost two feet off the ground, clinging to the iron hand locked around his throat. "You _think_ you can _know_ me." It's crushing, the pressure, the sheer _energy_ radiating off him like a smothering blanket, and Barry can't breathe at all, couldn't scream if he tried, and he's going to die like this, Zoom is going to kill him and Joe will never see him again and _Iris_.

"You are _nothing_."

Zoom drops him on the floor and he bangs up both knees, coughing against the carpet as he heaves, struggling for every breath. A kick sends him against the stairs, cracking ribs, and he's only vaguely aware of Zoom speaking as he curls inward, trying to breathe through the pain.

"You think you can stop me." Zoom doesn't laugh, but the way he huffs is almost amused. "You think _he_ can stop me."

Zoom drags Barry up by the front of his shirt and Barry groans, thinking that this must be what it feels like before being mauled to death by a large carnivore. A breathless sort of terror, utterly detached from reality, because he's seen a lot, some might even say too much, chasing meta-humans, but it's a far cry from being held by the most dangerous person – animal – _thing_ alive and knowing with certainty that no one can save him.

His glasses are cracked and there's a punishing pain in the back of his head, he hit it somewhere, but the adrenaline washes everything else away, lets him stare into the fuzzy face of Zoom.

"You are _nothing_."

Somewhere in the back of Barry's brain is agreement. The forefront is incinerated by pain, rational thoughts struggling to escape the fire. Everything hurts and he knows he's going to die but somehow he can't even bring himself to be upset as Zoom closes a hand around his throat.

"You are _no one_."

Pressure, and Barry wants to fight but he can't, it's bled out of him, so he hangs there, feeling consciousness slipping away from his breath by agonized breath.

"And you will _never_ be a hero."

Then there's a blast of yellow lightning, so intense it momentarily blinds Barry, and he feels someone close by as Zoom loosens his grip. He doesn't let go, though, and they're gone before Barry can take a breath.

 _The Flash is back_ , he thinks in his last aching moment of consciousness.

Then the world - goes - _dark._


	2. Chapter 1

_Earth Two. Tuesday evening, 8:00 PM._

 _One hour since abduction. One hour since landing._

"Good evening, everyone, I'm Adam Lark, and I'm coming to you _live_ with breaking news: we have just received reports of a _red streak_ sighted again in Central City. It seems like the Scarlet Speedster has finally returned home."

Iris doesn't speak, turning from her report to look up at the screen. A wild sort of elation is racing through her, burning up emotion in its wake, leaving only _determinacy._

 _He's back_.

She advances towards the TV screen as if it will become more tangible that way, as if she could join the war just by stepping forward, because Barry is right.

 _As long as Zoom is alive, people are going to get hurt._ (Patching up his own elbow, and she knows he's angry at the mugger who attacked him, can feel it in the tremble of his fingers as he sits in a chair and applies the bandage himself, but he's too focused on _something_ to feel it, looking at her with clear eyes.) _Iris . . . there has to be a fight. Someone has to stop him._

Oblivious to the surge of fierce joy in her chest at the thought that the Flash is _back_ , Lark continues.

"Spotted just outside S.T.A.R. Labs, the man only known as The Flash was seen briefly as responders arrived to investigate explosive activity on the premises. There were no casualties, but eyewitnesses say that they saw a 'red blur' identifiable as Central City's finest before The Flash disappeared."

 _Everyone_ is watching now, even Detective Singh, who scarcely looks away from his work unless someone attacked him – and, perhaps, not even then. The Flash's disappearance hit them hard; losing his fiancé hit Singh harder. There's a profound sense of _loss_ that clings to him, like he couldn't fight if his own life depended on it.

He didn't stay on the force because he loved the work. He stayed on the force to keep Zoom from hurting anyone else the way he'd been hurt.

And now there's a _fire_ in his eyes as he stares at the letters emblazoned across the bottom of the screen, _The Flash Returns_ , and it's like hope, like anguish, because maybe if the Flash had been there, he would've been able to save those people before the building collapsed, taking eighteen lives – including Robert's – with it.

The way his jaw is clenched, Iris is surprised it doesn't crack audibly.

"It is unclear where The Flash is now," Lark wraps. "Stay tuned for more on CCPN."

And Iris thinks, _I have to call Barry._

 _Flash is back._

Looking around the room, she knows: _It's time._

. o .

 _Earth Two. Friday morning, 7:00 AM._

 _Three days since abduction. Three days since landing._

There's an article on Barry's laptop.

It's not her place to read it before he publishes it, but curiosity wins her over. He hasn't been responding to her texts or calls, but she isn't worried. She knows how invested in his projects he can get, how his phone probably died hours ago and he'll come home flushed and apologetic but full of _stories_ , fantastic stories, and more often than not a scrape or bruise to attest to it.

He probably put this in his queue before taking off, anticipating a leave of absence. He's done it before – half of his articles are published while he's out on the street, interviewing people, trying to put together clues about why something _happened_ while Iris just tries to keep him from taking a bullet to the chest in pursuit of the truth.

Taking a sip from her coffee, Iris pulls up the tab labeled: _2-8-2016_.

 _FLASH_

 _Barry West-Allen_

 _To many of us, The Flash is just a red blur. But to the people whose lives he touches more directly, he is so much more than that: he is the man who pulls them from burning buildings, rushes them to the hospital, and reunites families. He is the one who helps contain the people we call 'meta-humans,' who uses his powers to advance our society instead of stunt it._

 _To many of us, he's still a stranger; to some of us, he may even be a friend, a rescuer, a personal guardian – but to all of us, The Flash is a hero._

 _The Flash isn't the only one out there. You know his name – you may never have seen him, but he exists – and you know that the only other person like him is The Flash. Zoom will stop at nothing to hurt the people you care about, to ruin all of our lives to get what he wants. If we don't fight him now, then he may never stop._

 _I know that The Flash disappeared. But I don't believe he abandoned us. I don't believe he gave up on this city or on us and left us to fight Zoom on our own._

 _I believe in things that are supposed to be impossible. I believe Zoom is who he says he is – the fastest man alive – but I know speed isn't everything. You can outrun a speeding bullet, but you can't outrun justice forever. It will catch up to him. Zoom's reign of terror will end. But we have to take a stand against him or we will be vulnerable to the next Zoom, to every Zoom out there._

 _In order to save this city, you need to do something._

 _You need to believe in—_

. . . Iris scrolls, searches the page for the rest, because it isn't like Barry to leave an article unfinished, but there isn't anything to find.

It just _ends_.

She hits save and closes it for him, knowing that he'll return to it when he gets home. Smiles softly, distantly amused at the idea that it's already outdated.

 _The Flash is back, Bar_.

But he isn't home to share the news with, and it's sobering for it.

. o .

 _Earth Two. Saturday afternoon, 12:35 PM._

 _Four days since abduction. Four days since landing._

The city waits with bated breath for more news, any news.

It doesn't come.

At Jitters Iris orders coffee for one and doesn't spill it down her front like Barry might have, but it's still seems more bitter for it. Flat.

Something fundamental is missing. Whether it's the Flash's sudden reappearance and anxiety-inducing silence or Barry's continued absence, Iris doesn't know.

It sits with her all day.

 _6:55 PM._

She sends the text.

 _Hey, Bar._

Then she waits, unable to think of a single word to say. Not _why did you leave_ or _why won't you come back?_

Just a light in the darkness that he does not find.

. o .

 _Earth Two. Monday evening, 8:00 PM._

 _Six days since abduction. Six days since landing._

"Good evening, everyone, I'm Kara Baker. It's been almost a week since The Flash was last seen and no further sightings have been reported.

"At this time, CCPD has not confirmed if the red blur we saw last Tuesday was indeed The Flash, even though eyewitnesses are adamant that they saw a streak of red just before an explosion tore out part of Star Labs' facilities. Sources have stated that it is possible the lightning was merely a technical malfunction or related to an isolated phenomenon.

"Meanwhile, we're expecting a chilly one this evening, with our high in the mid-forties and low in the low-thirties. Stay warm and indoors if you can."

Iris sits back against the couch, legs tucked underneath her, cradling a mug of hot chocolate between her hands. Her dad won't be home for another hour – he's been working late a lot recently, helping out, even though crime rates have remained almost eerily low. That's a good thing, Iris knows, but it doesn't sit well, knowing that they're in a lull before the storm.

Zoom is still out there. And while he is, everyone is still in danger.

The Flash's absence is sobering, but it's the coolness at her side where Barry should be that bothers her the most.

"I'm here at Central City Picture News with CCPD Captain Joe West for an update on the explosion at Star Labs," Baker continues, utterly nonplussed. "Captain West, thank you for joining us."

"Any time."

Her dad sounds almost as worn as she feels and Iris knows he's thinking about Barry, too. They have their own apartment, but it's comforting to spend time here whenever Barry's away. Their place just doesn't feel right without him.

This way, she can almost pretend he _is_ home. She can almost walk in and he'll try to apologize before she kisses him because God, Bar, just don't do that to me.

She can almost feel the way his back moves under her hands, the way he kisses back, the way his presence occupies her life, and she feels cooler and more exposed without him there.

No one outside her living room can hear how loud the silence is.

She turns up the volume on the TV to try and block it out.

"Captain West," Baker asks, "what can you tell us about Zoom's silence? Where _is_ The Flash?"

"The Flash's whereabouts remain unknown," her dad answers, picking his words carefully. "Zoom is also MIA. If we're lucky, he'll stay that way."

"Do you believe he will?"

A huff, almost a laugh. "No. I don't."

"How prepared would you say CCPD is in the event of another attack from Zoom?" Baker presses.

"Zoom is a class unto himself. It's hard to predict what would happen during a direct confrontation. At our current level of preparedness," a weighted pause, and Iris can almost feel the city hunkering down, bracing itself for the war as her dad finishes, "it could be catastrophic."

Even the anchor doesn't have anything to say for a beat, putting on a serious expression to mask her own unease as she presses, "If the Flash is back, should we expect to see a confrontation between them soon?"

"If he is back," her dad replies, echoing his words, "then it's almost inevitable. Zoom tried to kill him for two years. That sort of grudge doesn't just evaporate overnight."

"Why go after the Flash?"

Her dad almost smiles. "Because he's there. Another speedster represents a challenge. He's someone who can keep Zoom in check. Without him, Zoom doesn't have someone in direct competition with him. He can do as he pleases."

"And if—"

Baker pauses mid-sentence as _something_ out of their sightline catches her eye before saying with evident enthusiasm, "We have just received word that there has been another Flash sighting outside Star Labs." Turning to her dad, Baker notes, "This is starting to sound like it _wasn't_ an isolated phenomenon. Thoughts?"

"Let's hope so," is all her dad says, holding out a hand to shake on cue with the _8:15_ mark, accepting the thank-you-for-joining-us with a gracious smile that never reaches his eyes.

Baker says, "You heard it here live: there has been a _second_ Flash sighting outside of Star Labs."

Iris clicks off the TV, thinking, _Why are you hiding?_

She doesn't even know who she's speaking to anymore. The ache in her chest is the same.

Because there is a tiny, catastrophic corner of her mind saying, _He's never been gone this long before._

. o .

 _Earth Two. Tuesday afternoon, 2:45 PM._

 _One week since abduction. One week since landing._

Iris is at the precinct and it's quiet up here, her hands shaking with fatigue as she clicks away at her laptop, occasionally pausing for a sip of the coffee beside her. Midweek has been slow, tedious. It gives her too much time to think about him. Out of sight, out of mind only applies to certainties, things you expect to resolve peaceably. She can never quite banish him from her thoughts because there is _no_ certainty.

When Barry vanishes, she can only hope he will return.

Then she hears the footsteps, careful, methodical, and Iris stills, her heart skipping a beat as she presses save and closes the document. She can already feel the tears, the wave of _relief_ sweeping over her as she logs out of her computer with trembling fingers and stands, turning on legs that scarcely want to oblige to face him.

He is as beautiful as she remembers him.

All she can say in that devastating moment of recognition is _his name._

" _Barry._ "

He's walking slowly towards her, almost like he doesn't know fully how to approach his return, but she doesn't let him speak, just grabs him by the lapels of his coat and kisses him _hard_.

Reprimands can come later. Explanations can come later.

All that matters is that Barry's safe.

And he's finally, _finally_ home.

. o .

 _ **Earth One**_ _. Tuesday evening, 6:45 PM_.

 _One week since abduction. One week since departure._

If only, if only, if only.

Iris stares at the place where Barry should be, standing in the middle of Star Labs, and she can still see his face.

 _Iris. I have to go._

 _He'll kill you._ (She's holding onto his coat as tightly as she can as if she can keep him there, because Bar, don't do this, I-lost-Eddie-I-can't-lose-you-too, don't _do this_.)

 _Iris._ (He's got his hands over hers. Rubbing slowly. Closing them around her hands, gaining the upper hand.) _He took Patty. I don't have a choice_.

(She fists his coat, tries not to see him leaving because he _can't go_ , if he leaves he might never come back.) _You could lose your speed, you could lose your_ mind—

(He takes her head in his hands so gently, presses a lingering kiss to her forehead.) _Iris._ (Slides his hands down to her wrists, very firmly pulling them off – neither painful nor uncomfortable, but _inexorable_ , and she forgets, sometimes, that he's strong enough to punch steel and carry cops twice his size to hospitals.) _I love you._ (Squeezes her hands once before letting them go and she's reaching for him even as he steps back, squares his shoulders.) _I'm coming back_.

"Iris?"

She turns and Wally is there, looking almost shy as he glances around the room inquisitively. "Everything okay? Are they back?"

Iris shakes her head, feeling the shadow of a smile. "No."

Wally steps closer, hands in his pockets, not sure what to do but wanting to be closer. "Is there any way I can make it easier?" he asks.

Iris isn't expecting it – wants him to say _it'll be okay_ just so she can get angry, because she shouldn't but God, she's angry, Barry's been gone for a week, all of them have, and if he never comes back she'll spend the rest of her life waiting for him – but when Wally steps closer she doesn't lash out.

Instead, she hugs him, holding onto him, telling herself, _He's still here. You've got one of them._

The warmth and strength radiating from him makes her think of Barry so much it hurts. He's got that same _lightning-under-his-skin_ feel, like he's overflowing with vitality, and it's comforting. Like somehow as long as Wally is alive and well, maybe Barry is, too.

All Iris says is, "I'm really glad you're here, Wally."

Wally squeezes her lightly, lets her go, and says quietly, "We should get back." Then, thoughtfully, he adds, "Dad's making lasagna and I'm supposed to eat two trays' worth of it?"

Iris lets out a wordless huff of amusement in spite of herself, almost a laugh.

"Yeah, he's used to cooking for twelve."

"Big family dinners?"

Iris pictures Barry devouring four whole boxes of pizza over an hour, _taking his time_ , and can't resist the genuine smile it elicits. "You could say that," she muses.

She remembers the Arrow team coming over (once, but it was memorable) and how chaotic _that_ dinner was, especially since Oliver insisted that between Diggle and he they could still take Barry down over spicy chicken wings. (They totally did. Barry drank an entire gallon of milk to get the burn out of his mouth while Dig and Oliver high-fived before rewarding themselves with cleaning up the dishes while Felicity ate most of Oliver's share of cake.)

"We're just used to having a superhero in the house," she explains, leading the way towards the exit. "I'm sure he doesn't _actually_ expect you to eat all of it."

. o .

"Oh, I expect you to eat all of it," her dad deadpans, setting an entire tray of lasagna in front of Wally, his expression torn between anticipation and fear. "You, too," he adds, grinning at Iris. "Growing kids, you know."

"Not a kid," she reminds, pointing a fork at him and accepting the hug as he wraps his arms around her shoulders, leaning his head on hers for the briefest moment before letting her go.

"You're _always_ gonna be my kids," he points out.

It's a comforting thought, knowing _who_ she has on her side.

If she had to pick allies, she doesn't see herself doing between than her dad and Wally.

 _You better come back, Bar,_ she thinks, sitting on the couch next to Wally as he talks sports with her dad, keeping up an air of nonchalance perfectly.

 _Or we're coming after you_.


End file.
